Oil demand in the world's third-biggest economy has been declining gradually for more than a decade, reflecting a falling population and a shift to more efficient vehicles and equipment.

Japan's crude oil imports in April rose 1.8 percent from a year earlier to 3.53 million barrels per day (16.84 million kilolitres), marking the first year-on-year gain in three months, the data showed.

Meanwhile, Japan imported South Blend crude from Colombia and Zhaikmunai condensate from Kazakhstan for the first time last month, a METI official said.